Terminal block



April 2, 1957 c, POTTER 2,787,773

TERMINAL BLOCK Filed Aug. 11, 1953 IN VEN TOR.

Donald Z2 22 C I Fig. 3 I

TERMINAL BLOCK Donald C. Potter, Everett, Wash.

Application August 11, 1953, Serial No. 373,594 K 8 Claims. (Cl.339-198) This invention relates to terminal blocks for use in electricwiring, and for its general objects aims to provide a block of unusuallysimple design which can be produced inexpensively and which etficientlyperforms its intended function.

A further important object is to devise a terminal block having wideadaptability in that the same can be conveniently mounted in locationswhich have been troublesome with previously existing terminal blocks.

As a further particular object the invention aims to provide a terminalblock composed of a plurality of complementing sections which admit ofbeing used either singly or back-to-back one in conjunction with anotherand wherein the back-to-back components, for any given length, areidentical and thus preclude the necessity for right and left hand moldsas well as obviating any need for stocking of right and left handblocks.

With the foregoing ends in view the invention consists in the novelconstruction, adaptation and combination of parts as will be hereinafterdescribed and claimed.

In the accompanying drawing:

Figure 1 is a top plan view of a terminal block installation using blocksections constructed to embody the preferred teachings of the presentinvention, with wires shown attached to several of the terminals.

Fig. 2 is a view on line 2-2 of Fig. 1 to show one of the block sectionsin rear elevation.

Figs. 3 and 4 are transverse vertical sectional views on lines 3-3 and4-4, respectively, of Fig. 1.

Fig. 5 is a perspective view portraying a return type bus bar employedin those instances in which the terminal block is made up from only asingle block section or a plurality of in-line block sections asportrayed in Fig. 4; and

Fig. 6 is a view portraying in perspective two straight type bus barsemployed in those instances in which the terminal block is made up fromblock sections placed in back-to-back relation as portrayed in Fig. 3.

According to the present invention there are provided a plurality ofblock sections adapted to be used singly or in multiples, and thesesections are by preferance made in only two lengths, one being aS-circuit section, designated generally by the numeral 10 and the othera 10- circuit section, designated generally by 11. Sectionsaccommodating a greater or a lesser number of circuits could, ifdesired, perforce be provided. All block sec tions of a correspondinglength are identical.

The block sections are molded to shape from any suitable insulatingmaterial as, for example, fibreboard, Bakelite or the like, and havesomewhat the shape of a right angled triangle when viewed in endelevation, with the base and the vertical leg of the figure serving asthe bottom 12 and rear wall 13, respectively, of the block section. Ateach end of the block section there is provided a wing extension havingan angular shape when viewed from the end, and piercing the horizontalleg 15 and the vertical leg 16 which each of these wing nited StatesPatent- 0 2,787,773 v Patented Apr. 2, 1957 2- extensions provide is avertical hole 17 and a horizont hole 18, respectively, accommodating amounting screw 20 in the instance of the hole 17 and a nutted clampingbolt 21 in the instance of the hole 18. Between such wings the rear wallof the block section presents rectangular recesses 22 located more orless centrally of the height at equidistantly spaced intervals of thelength. There is provided one such recess for each of the severalcircuits, five or ten as the case may be, for which the block section isdesigned. Designated by 23 are upper and lower series of alignedhalf-circle grooves let into the partitions 24 which separate saidrecesses one from another and from the side edges of the block section.

In transverse alignment with each of the several backwall recesses 22the front wall of the block section is stepped to produce an upper and alower offset 25 and 26, respectively, disposed in approximate horizontalalignment with the upper and the lower limit, respectively, of therelated rear-wall recess, and disposed flush with the offsets andextending as prolongations therefrom to the rear-wall recesses there areprovided upper and lower slots 27 and 28, respectively. The ofisetsfurnish seats for the vertically tapped extremities of bus bars, andbinding screws 29 threaded in these tapped openings are accommodated bycavities 30 formed in the body of the block section. Each seat isseparated from the next adjacent seat in the row by upstandingpartitions 31.

The block sections of the present terminal block may be used'singly orthey may be used in multiple, and when used in multiple the sections maybe applied either end-to-end or back-to-back, the single or end-to endmultiple usage being usually confined to those installations in whichthe available space is quite narrow or where the space to be occupiedlies in the angle defined between two meeting walls so that both thebottom surface and the back surface of the terminal block each bearagainst a wall. In such installations the bus bar shown in Fig. 5,hereinafter termed a return bus bar, is employed. This bus bar issomewhat suggestive of a yoke with a cross-arm 32 connecting parallelside branches 33 and 34, and is so shaped and dimensioned that thecross-arm fits within the recess 22 and the two branches 33 and 34extend through the slots and position their extremities on the seats 25and 26 with the tapped openings registering with the cavities 30. Twolead wires of a single said circuit such as I denote by 35 and 36 inFig. 1 are connected by the binding screws to these exposed bus'barextremities. For those installations which more especially lendthemselves to a backto-back association of two block sections, the sameare secured one to the other by the clamping bolts 21 and the straightbus bars are provided in two lengths, with the shorter bar 37 beingarranged to extend from the upper seat 25 of one block section throughcommunicating slots 27-27 to the upper seat 25 of the other blocksection, and with the longer bar 38 being arranged to extend from thelower seat 26 of one block section through communicating slots 2$28 tothe lower seat 26 of the other block section. Two sets of two lead wiresfor respective electric circuits are, for this type of installation,designated in Fig. 1 by 40--4 1 and 42-43. The function of the notches23 is to afford ventilation openings for the box cavities produced bythe recesses 22 when two such recesses are brought into registration.

Marking strips 45 are or may be provided to facilitate theidentification of the binding posts.

It is thought that the invention and the manner of its usage will havebeen clearly understood from the foregoing detailed description of mynow-preferred illustrated embodiment. Changes in the details ofconstruction will weaves suggest themselves and I accordingly intendthat no.

limitations be implied and that the hereto annexed claims be given thebroadest interpretation which the employed language fairly permits;

What I' claim is: t

1. In a terminal block, .a unitary stepped bodylprovided in its frontwall with an upper and-a lower' longi tndinal series of exposed shelveshaving each series occupying a respective step of the body and with eachshelf in the upper series being transversely aligned with a relatedshelf in the lower series and having slots extending parallel with oneanother rearwardly from each pair of related shelves and each exposed tothe rear of the body, and a respective U-shaped bus bar for each pair ofrelated shelves, the bus bars presenting tapped openings in eachextremity and being so dimensioned that the side branches of the Uclosely fit the parallel'slots and seat the tapped extremities upon therelated shelves.

2. The block of claim 1 in which the shelves each present a cavitydisposed normal to'the shelf and accommodating the, projecting end of abinding screw threaded in the tapped extremity of an applied bus bar.

3. In a terminal block, a unitary block body provided in its front Wallwith an upper and a lower longitudinal series of exposed shelvesseparated one from another shelf in each series by upstanding partitionsand with each shelf in the upper series being transversely aligned witha related shelf in the lower series, the body having slots extendingrearwardly from each pair of related shelves each exposed to the rear ofthe body, and a respective U- shaped bus bar for each pair of relatedshelves, the bus bars presenting tapped openings in each extremity andbeing so dimensioned that the side branches of the U extend inclose-fitting engagement through the slots to the shelves and seat thetapped extremities upon the related shelves.

4. In a terminal block, a block body provided in its front wall with anupper and a lower longitudinal series of exposed shelves separated onefrom another shelf in each series by upstanding partitions and with eachshelf in the upper series being transversely aligned with a relatedshelf in the lower series, the body having slots extending rearwardlyfrom each pair of related shelves each exposed to the rear of the body,and a respective U- shaped bus bar for each pair of related shelves, thebus bars presenting tapped openings in each extremity and being sodimensioned that the side branches of the U extend in close-fittingengagement through the slots to the shelves and seat the tappedextremities upon the related shelves, the shelves each presenting acavity in the floor thereof accommodating the projecting end of abindfor each of said pairs of related upper and lower shelves,

a let-in cavity exposed to the rear, and having parallel slots for eachof said pairs of related shelves connecting the shelves with the relatedcavities, and a respective U- shaped bus bar for each pair ofrelatedshelves, the bus bars presenting tapped openings in each extremity andbeing so dimensioned that the cross-arm of the U occupies the cavity andthe side branches of the U extend in close-fitting engagement throughthe slots and seat the tapped extremities upon the related shelves.

6. A terminal block comprising, in combination: a pair of identicalblockbodies having their back faces recessed to provide'equidistantly spacedseparated cavities exposed to the rear, provided in the front wall witha respective upper and lower shelf transversely aligned with each ofsaid cavities, and having parallel slots connecting the shelves with therelated back cavities, means securing said blocks in back-to-backrelation with the back cavities in registration, and straight bus barsextending through said communicating slots from the shelves of one tothe shelves of the other of said back-to-back block bodies, the appliedbus bars presenting tapped openings in each extremity exposed for theapplication of binding screws.

7. The terminal block of claim 6 in which a cavity is recessed into thefloor of each shelf to accommodate the projecting end of an appliedbinding screw and lock the related bus bar against endwise displacement.

8. The terminal block of claim 6 in which partitions separating the backcavities one from another and from the side edges of the block bodiesare grooved in a direction longitudinally of the body to provideventilation openings for the back cavities of the terminal block.

ReferencesCit'ed in the file of this patent UNITED STATES PATENTS456,611 Balsey July 28, 1891 1,517,017 Roth Nov. 25, 1924 2,134,402Hines Oct. 25, 1938 2,221,710 Johnson Nov. 12, 1940 2,397,102 Graham -1Mar. 26, 1946 2,411,014 Warnke Nov. 12, 1946 2,495,279 OBrien et a1.Jan. 24, 1950

